U.S. patent application number 11/421653 was filed with the patent office on 2006-09-14 for balloon catheter for multiple adjustable-length stent deployment.
This patent application is currently assigned to Xtent, Inc.. Invention is credited to Israel Chermoni.
Application Number | 20060206190 11/421653 |
Document ID | / |
Family ID | 11075281 |
Filed Date | 2006-09-14 |
United States Patent
Application |
20060206190 |
Kind Code |
A1 |
Chermoni; Israel |
September 14, 2006 |
BALLOON CATHETER FOR MULTIPLE ADJUSTABLE-LENGTH STENT
DEPLOYMENT
Abstract
A catheter configured to carry one or more stents and having an
inflatable balloon for expanding a stent surrounding the balloon.
The catheter is characterized in having a positioner for moving the
one or more stents relative to the balloon from a first position in
which the stent does not surround the balloon to a second position
in which the stent surround the balloon. Also disclosed is a method
for deploying a stent at a desired location in the vascular
system.
Inventors: |
Chermoni; Israel; (Haifa,
IL) |
Correspondence
Address: |
ORRICK, HERRINGTON & SUTCLIFFE, LLP;IP PROSECUTION DEPARTMENT
4 PARK PLAZA
SUITE 1600
IRVINE
CA
92614-2558
US
|
Assignee: |
Xtent, Inc.
|
Family ID: |
11075281 |
Appl. No.: |
11/421653 |
Filed: |
June 1, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10108985 |
Mar 29, 2002 |
|
|
|
11421653 |
Jun 1, 2006 |
|
|
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Current U.S.
Class: |
623/1.11 |
Current CPC
Class: |
Y10S 623/903 20130101;
A61F 2/958 20130101; A61F 2002/826 20130101; A61F 2/95
20130101 |
Class at
Publication: |
623/001.11 |
International
Class: |
A61F 2/06 20060101
A61F002/06 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 29, 2001 |
IL |
142332 |
Claims
1. A stent delivery system comprising: a catheter having a distal
end and an inflatable balloon near the distal end for expanding a
stent surrounding the balloon, the catheter carrying a plurality of
stents and having a positioner slidable longitudinally along the
catheter independently of said plurality of stents for moving said
plurality of stents relative to said balloon from a first position
proximal to the distal end to a second position closer to the
distal end in which at least one of said plurality of stents
surrounds the balloon, the stents being independently deployable
from each other such that the at least one stent may be expanded by
the balloon while at least a second stent is retained on the
catheter, the catheter further having a separating member adapted
to separate the at least one stent from the second stent to allow
expansion of the at least one stent.
2. The stent delivery system according to claim 1 wherein the
stents are adapted to be deployed in a blood vessel in any
order.
3. The stent delivery system according to claim 1 wherein the
positioner comprises a sliding element configured to slide
longitudinally along the catheter and push the plurality of stents
distally along the catheter so as to move a stent adjacent to the
balloon into a position in which it surrounds the balloon.
4. The stent delivery system according to claim 3 wherein the
sliding element is attached to a wire extending longitudinally
along the length of the catheter and the sliding element slides
along the catheter in response to a longitudinal movement of the
wire.
5. The stent delivery system according to claim 1 comprising two
positioners, a posterior positioner positioned posterior to the
balloon and an anterior positioner positioned anterior to the
balloon.
6. The stent delivery system according to claim 5 wherein said
anterior positioner is adapted to be distanced from the balloon so
as to provide a storage space between the anterior positioner and
the balloon.
7. The stent delivery system according to claim 1 wherein said
balloon has an expandable portion having a length that is
adjustable to be coextensive with the length of the at least one of
said plurality of stents.
8. The stent delivery system according to claim 1, wherein the
length of said at least one of said plurality of stents is
different than at least one other of said plurality of stents.
9. A stent delivery system comprising: a catheter having a distal
end and an inflatable balloon near the distal end for expanding a
stent surrounding the balloon, the catheter carrying a plurality of
stents and having a positioner slidable longitudinally along the
catheter and adapted to engage only a proximal stent of said
plurality of stents to move said plurality of stents relative to
said balloon from a first position proximal to the distal end to a
second position closer to the distal end in which at least one of
said plurality of stents surrounds the balloon for deployment
therefrom, the stents being independently deployable from each
other such that the at least one stent may be expanded by the
balloon while at least a second stent is retained on the catheter,
the catheter further having a separating member adapted to separate
the at least one stent from the second stent to allow expansion of
the at least one stent.
10. The stent delivery system according to claim 9, wherein the
stents are adapted to be deployed in a blood vessel in any
order.
11. The stent delivery system according to claim 9, wherein the
positioner comprises a sliding element configured to slide
longitudinally along the catheter and push the plurality of stents
distally along the catheter so as to move said plurality of stents
from the first position to the second position.
12. The stent delivery system according to claim 11, wherein the
sliding element is attached to an elongated member extending
longitudinally along the length of the catheter and the sliding
element slides along the catheter in response to a longitudinal
movement of the elongated member.
13. The stent delivery system according to claim 9, wherein said
balloon has an expandable portion having a length that is
adjustable to be coextensive with the length of the at least one of
said plurality of stents.
14. The stent delivery system according to claim 9, wherein the
length of said at least on of said plurality of stents is different
than at least one other of said plurality of stents.
15. The stent delivery system of claim 9, wherein the length of the
stent deployed by the catheter is selectable.
16. A stent delivery system comprising: a catheter having a distal
end and an inflatable balloon near the distal end for expanding a
stent surrounding the balloon, the catheter carrying a plurality of
stents and having a positioner slidable longitudinally along the
catheter for moving said plurality of stents relative to said
balloon from a first position proximal to the distal end to a
second position closer to the distal end in which at least one of
said plurality of stents surrounds an expandable portion of the
balloon, the stents being independently deployable from each other
such that the at least one stent may be expanded by the balloon
while at least a second stent is retained on the catheter, the
catheter further having a separating member adapted to separate the
at least one stent from the second stent to allow expansion of the
at least one stent, wherein the length of the expandable portion is
adjustable to be generally coextensive with the length of the at
least one stent.
17. The stent delivery system according to claim 16 wherein the
stents are adapted to be deployed in a blood vessel in any
order.
18. The stent delivery system according to claim 16 wherein the
positioner comprises a sliding element configured to slide
longitudinally along the catheter and push the plurality of stents
distally along the catheter so as to move a stent adjacent to the
balloon into a position in which it surrounds the balloon.
19. The stent delivery system according to claim 18 wherein the
sliding element is attached to an elongated member extending
longitudinally along the length of the catheter and the sliding
element slides along the catheter in response to a longitudinal
movement of the elongated member.
20. The stent delivery system according to claim 16, wherein the
length of said at least one of said plurality of stents is
different than at least one other of said plurality of stents.
21. The stent delivery system according to claim 16, further
comprising a constraining member slidable over said balloon,
wherein the constraining member constrains a portion of the balloon
from expanding.
Description
RELATED APPLICATION DATA
[0001] This application is a continuation of U.S. patent
application Ser. No. 10/108,985, filed Mar. 29, 2002, which
application is hereby incorporated by reference in its
entirety.
FIELD OF THE INVENTION
[0002] This invention relates to catheters and more specifically to
such catheters that are used to implant a stent in an artery.
BACKGROUND OF THE INVENTION
[0003] Blood vessels, and particularly arteries, may become
stenotic or occluded due to various atherosclerotic processes. A
stenotic artery may be treated by balloon angioplasty in which an
inflatable balloon mounted on a catheter tip is inserted into the
arterial system and navigated through the arterial system to the
diseased artery. The balloon is then inflated by means of a
pressurized fluid. This causes the balloon to press radially on the
arterial wall so as to open the stenosis. A stent may be crimped
onto the balloon before insertion so that when the balloon is
inflated the stent becomes expanded, The balloon is deflated and
withdrawn leaving the expanded stent in the artery. These and other
similar methods are well known to the skilled man of the art.
[0004] It is often necessary to treat several stenoses in a single
angioplastic session. For example, it may be necessary to insert a
large diameter stent at one location, a small diameter stent at a
second location and to perform a balloon angioplasty without a
stent at a third location. This could be accomplished by sequential
insertion and withdrawal of a catheter, the catheter being loaded
each time with the appropriate stent prior to insertion. This
however would cause much discomfort to the patient, prolongs the
duration of the procedure and increases the chances of damaging a
blood vessel.
[0005] U.S. Pat. No. 6,027,519 discloses a catheter for deploying
one or more stents. The stent has one or more individually
expandable segments along its length. A stent, in its unexpanded
states is loaded onto each expandable segment of the catheter. The
catheter is inserted into the vascular system and positioned with
the first expandable segment in a stenosis. An axial force is then
applied to the segment causing it to buckle outwards and expand the
stent. The force is then removed caused the segment to unbuckle
leaving the stent in its expanded state. The catheter is then
navigated to another stenosis. This process is repeated until all
of the stents have been deployed.
SUMMARY OF THE INVENTION
[0006] The present invention provides a catheter for deploying one
or more stents in a cardiovascular system. The catheter is
configured to carry one or more stents. Preferably, the catheter
carries a plurality of stents. The stents may be of different or
the same widths. An inflatable balloon is used to expand a stent
surrounding the balloon. The catheter comprises a positioner for
moving a stent relative to the balloon from a position in which the
stent does not surround the balloon to a position that it does
surround the balloon in order to prime the stent for expansion by
the balloon. The phrase "for moving a stent relative to the
balloon" includes two possibilities, i.e. moving the positioner
relative to the balloon and moving the balloon relative to the
positioner.
[0007] In one embodiment of the invention the positioner comprises
an element configured to slide along the catheter and push the
stents distally along the catheter so as to move a stent adjacent
to the balloon into a position in which it surrounds the balloon.
The sliding element is pushed along the catheter by means of a wire
extending along the catheter from its proximal end to the sliding
element. In this embodiment, the stems are deployed in the order in
which they are carried by the catheter, starting with the stent
closest to the balloon.
[0008] In another embodiment, the positioner comprises a flexible
carriage configured to carry the one or more stents. The carriage
is capable of sliding along the catheter in order to bring one of
the stents from a position in which the stent does not surround the
balloon to a position in which the stent surrounds the balloon. The
carriage is moved in either direction along the catheter by means
of a wire extending along the catheter from its proximal end to the
carriage. It is also possible to position the stent opposite a
desired location in the vascular system and slide the balloon
through the carriage to a position opposite the stent. In this
embodiment the stents may be deployed in the vascular system in any
order.
[0009] It a third embodiment, the catheter comprises two
positioners, one posterior positioner as described above in the
first embodiment positioned posterior to the balloon, and a second
anterior positioner positioned anterior to the balloon. In this
embodiment, the anterior positioner may be distanced from the
balloon so as to provide a storage space between the anterior
positioner and the balloon. The balloon in this embodiment may be a
conventional balloon used in balloon angioplasty. In this
embodiment also, the stents may be deployed in the vascular system
in any order, and may be of different lengths.
[0010] In use, the catheter is loaded with one or more stents and
inserted into a vascular system. The catheter is navigated through
the vascular system until the balloon or stent is positioned at a
first desired location, typically the site of a stenosis. The stent
or balloon is then moved by the positioner so that the stent
surrounds the balloon and the balloon is inflated so as to expand
the stent. The balloon is then deflated, leaving the expanded stent
at the fist desired location. This process may be repeated, each
time deploying a different stent at a different location. After one
or more of the stents have been deployed, the catheter may be
removed from the vascular system.
[0011] The invention also provides a method for deploying a stent
in a desired location of a vascular system comprising the steps
of:
[0012] (a) inserting a catheter according to the invention carrying
one or more stents into the vascular system,
[0013] (b) navigating the catheter through the vascular system
until the balloon is positioned in the desired location;
[0014] (c) moving a stent from a first position in which it does
not surround the balloon to a second position in which it surrounds
the balloon;
[0015] (d) inflating the balloon so as to expand the stent; and
[0016] (e) deflating the balloon.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to understand the invention and to see how it may
be carried out in practice, a preferred embodiment will now be
described, by way of non-limiting examples only, with reference to
the accompanying drawings, in which:
[0018] FIG. 1 shows a catheter in accordance with one embodiment of
the invention;
[0019] FIG. 2 shows the catheter of FIG. 1 carrying stents;
[0020] FIG. 3 shows the catheter at FIG. 1 inserted in a blood
vessel;
[0021] FIG. 4 shows the catheter of FIG. 1 with a stent surrounding
a balloon on the catheter;
[0022] FIG. 5 shows the catheter in FIG. 1 after inflation of the
balloon;
[0023] FIG. 6 shows a catheter in accordance with another
embodiment of the invention;
[0024] FIG. 7 shows the catheter of FIG. 6 carrying stents;
[0025] FIG. 8 shows the catheter at FIG. 6 inserted in a blood
vessel;
[0026] FIG. 9 shows the catheter of FIG. 6 with a stent surrounding
a balloon on the catheter;
[0027] FIG. 10 shows the catheter in FIG. 6 after inflation of the
balloon;
[0028] FIG. 11 is a sectional side view of a catheter in accordance
with another embodiment of the invention;
[0029] FIG. 12 illustrates the operation of the embodiment
illustrated in FIG. 11; and
[0030] FIG. 13 illustrates another detail of the operation of the
embodiment of FIG. 11.
DETAILED DESCRIPTION OF THE INVENTION
EXAMPLE I
[0031] FIG. 1 shows a catheter 100 for deploying stents in
accordance with one embodiment of the invention. The catheter 100
has a distal end 108 and a proximal end 120. The catheter 100
comprises a flexible tube 102, which is connected to an inflatable
balloon 104 proximate to its distal end. The balloon 104 is shown
in the Figure in its deflated state. A radio-opaque marker 118 is
located on the balloon wall. The catheter 100 has at its distal end
108 a tapered tip 110 that may be inserted into a stenosis in order
to open the stenosis. A syringe 130 may be used to introduce a
fluid into the tube 102 in order to inflate the balloon 104 as
described in detail below.
[0032] A longitudinal shaft 124 in the wall of the tube 102 is
configured to receive a guidewire 126 used in navigating the
catheter in the vascular system. A neck region 122 of the tube 102
intervenes between the distal end of the balloon 104 and the tip
110. The proximal end of the tip 110 is broadened to form a
shoulder at the distal end of the neck region 122. A sliding
positioner element in the form of an annular sliding ring 114 is
mounted on the tube 102 proximal to the balloon 104. The ring 114
is slidable along the tube 102 by means of a wire 116 that extends
along the length of the tube 102 from the proximal end 120 of the
catheter to the ring 114.
[0033] The sliding ring 114 and the wire 116 form a positioner for
moving a stent from a position which it does not surround the
balloon 104 to a position in which it surrounds the balloon
104.
[0034] FIG. 2 shows the catheter 100 having a plurality of stents
(three are shown in FIG. 2) 206a, 206b and 206c, mounted on the
tube 102 between the sliding ring 114 and the balloon 104. The
stents are separated from each other by separating rings 208a and
208b. The sliding ring 114 has been positioned so that the
separating rings 208a and 208b and the stent 206 are contiguous
with the balloon 104. Each stent 206 bears a radio-opaque markers
210a, 210b and 210c.
[0035] In use, the catheter 100 is introduced into the vascular
system and navigated to a stenosis by methods well known in the
art. FIG. 3 shows the catheter 100 after having been navigated
through the vascular system and positioned inside a blood vessel
202. The balloon is located opposite a stenotic region 204 of the
blood vessel 202. The wire 116 is used to slide the sliding ring
114 distally along the tube 102 so as to push the stents 206a,
2066, 206c, distally. The sliding ring 114 is pushed distally along
the tube 102 so that the stent 206a is pushed over and around the
balloon 104, which is thereby brought into the lumen of the stent
206a, and the marker 118 on the balloon coincides with the marker
210a of the stent, as determined for example by x-ray angiography.
FIG. 4 shows the stent 206a surrounding the balloon 104.
[0036] A fluid is then introduced into the tube 102. The fluid
passes through the tube 102 and inflates the balloon 104. It will
be understood that the balloon may be inflated by other
conventional means, as are known in the art. Inflation of the
balloon 104 expands the stent 206a onto the stenotic region of the
blood vessel 202, as shown in FIG. 5.
[0037] The fluid is then withdrawn from the tube 102. Withdrawal of
the fluid from the tube 102 causes the balloon to deflate. After
deflation of the balloon, the stent 206a remains in situ in its
expanded state.
[0038] The catheter may then be navigated through the arterial
system until the catheter is positioned with the balloon 104 at.
another stenotic region of a blood vessel. The sliding ring is
pushed distally by the wire 116 so that the succeeding stent 206b
overlies the balloon 104 and the marker 118 coincides with the
marker 210b on the stent 206b. The distal separating ring 208a is
pushed along the tube 102, beyond the balloon 104 to the neck
region 122 of the tube, where the separating rings are stored. The
shoulder of the tip 110 retains the separating rings on the neck
region. This process may be repeated until some or all of the
stents 206 have been deployed. The catheter is then removed from
the body.
EXAMPLE II
[0039] FIG. 6 shows a catheter 600 for deploying stents in
accordance with another embodiment of the invention. The embodiment
of FIG. 6 has many components in common with the embodiment of FIG.
1, and similar components are identified by the same reference
numeral in both embodiments.
[0040] The embodiment of FIG. 6 has a cylindrical carriage 605
mounted on the tube 102. The carriage has a plurality of annular
depressions (three are shown in FIG. 6) 610a, 610b and 610c
configured to receive a stent as described below. The depressions
610 all have the same length A as indicated in FIG. 6, which is
essentially equal to the length of the balloon 104. Between the
depressions 610 are barriers 620a and 620b. The carriage 605 is
made from an elastic material such as rubber. The carriage 605 is
slidable along the tube 102 by means of a wire 116 that extends
along the length of the tube 102 from the proximal end 120 of the
catheter to the carriage 605. The carriage 605 and the wire 116
form a positioner for moving a stent from a position in which it
does not surround the balloon 104 to a position in which it
surrounds the balloon 104.
[0041] FIG. 7 shows the catheter 600 having a plurality of stents
(three are shown in FIG. 7) 206a, 2066 and 206c mounted on the
annular depressions of the tube 102. The stents are separated from
each other by the barriers 620a and 620b. In the present embodiment
the stents are of different lengths. However, they may also be of
the same length. Each stent 206 bears a radio-opaque annular marker
210a, 2106 and 210c.
[0042] The catheter 600 is introduced into the vascular system and
navigated to a stenosis by methods well known in the art. FIG. 8
shows the catheter 600 after having been navigated through the
vascular system and positioned inside a blood vessel 202. The
balloon is located within a stenotic region 204 of the blood vessel
202. The wire 116 is used to slide the cage 605 distally along the
tube 102 so as to move the stents 206 distally. The carriage 605 is
pushed distally along the tube 102 until the balloon 104 is brought
into the lumen of the stent 206a and the marker 118 on the tube
coincides with the marker 210a, as determined for example by x-ray
angiography. In a similar manner, the balloon may be slid within
the carriage until it is positioned opposite the stent. FIG. 9
shows the stent 206a surrounding the balloon 104.
[0043] A fluid is then introduced into the tube 102. The fluid
passes through the tube 102 and inflates the balloon 104. Inflation
of the tube 104 expands the portion of the carriage 605 surrounding
the balloon 104 which in turn expands the stent 206a onto the
stenotic region of the blood vessel 202, as shown in FIG. 10.
[0044] The fluid is then withdrawn from the tube 102 into the
syringe 130. Withdrawal of the fluid from the tube 102 causes the
balloon to deflate. After deflation of the balloon, the stent 206a
remains in its expanded state.
[0045] The catheter is then navigated through the arterial system
until the catheter is positioned with the balloon 104 in another
stenotic region of a blood vessel. The catheter is then pushed
distally by the wire 116 so that the stent 206b overlies the
balloon 104 and the marker 118 coincides with the marker 210b on
the stent 206b. In this embodiment, the stents may be deployed in
any order. This process may be repeated until some or all of the
stents 206 have been deployed. The catheter is then removed from
the body.
EXAMPLE III
[0046] This example illustrates an embodiment which is an
improvement over the embodiment described in Example I. With
reference to FIG. 11, there is shown a catheter 700 having a distal
end 108 and a proximal end 120. As in FIG. 1, the catheter 700
comprises a flexible tube 102, which is connected to an inflatable
balloon 704 proximate to its distal end. A radio-opaque marker 118
is located on the balloon wall. The catheter 700 has at its distal
end 108 a tapered tip 110, but unlike in Example I, there is no
neck region, and the tip is not enlarged. The balloon in this
embodiment may be a conventional inflatable balloon used in balloon
angioplasty.
[0047] As in Example I, a guidewire 126 extends along the tube 102,
exiting at the distal end 108 of the catheter. An anterior
positioner in the form of a perforated sphere 706 is fixed to the
guidewire anterior to the balloon 704, e.g. the guidewire passes
through a bore channel extending through the sphere. The diameter
of the sphere is slightly larger than the diameter of the retracted
stents which are mounted on the catheter. The purpose of the sphere
will be explained below.
[0048] The catheter 700 has a slicing ring 114 (being the posterior
positioner) and a plurality of stents (three are shown in FIG. 11)
206a, 2066 and 206c, mounted on the tube 102 between the sliding
ring 114 and the balloon 704. While the anterior stents are
generally of the same length, the posterior stent may be longer or
shorter. In the illustrated embodiment, the posterior stent 206c is
shorter than the other stents. Each stent 206 bears at least one
radio-opaque marker 210a, 2106 and 210c, respectively. The stents
are separated by separating rings 708a and 708b which are of the
same length as the anterior stents. An anterior ring 710 is
positioned between the most anterior stent 206a and the balloon 704
and protects the distal edge of the anterior stent. This anterior
ring may be shorter than the separating rings.
[0049] The operation of this embodiment may be under-stood with
reference to FIG. 12. As in Example I, the wire 116 is used to
slide the sliding ring 114 distally along the tube 102 so as to
push the stents 206a, 206b, 206c, distally. The sphere 706 is
distanced from the distal end 108 of the catheter by pushing the
guidewire 126, thus providing free guidewire 712 on which
components of the catheter may be stored. In FIG. 12, it may be
seen that the anterior ring 710 and the separating ring 708a have
been pushed beyond the balloon 704 and onto the free guidewire 712.
The anterior stent 206a (not shown) has been expanded and deployed
within the blood vessel wall, and the middle stent 2066 is mounted
on the balloon 704, ready to be expanded. The radio-opaque marker
210b of the stent 206b is positioned opposite the radio-opaque
marker 118 of the balloon 704.
[0050] Thus, this embodiment also differs from that of Example I in
having more room to store the separating rings. In addition, all of
the mounted stents and rings may be moved distally and proximally
by pulling and pushing the anterior and posterior positioners,
being the sphere 706 and sliding ring 114, respectively, so that
the stents may be deployed in any order. This differs from Example
I where the stents were required to be deployed in the order in
which they were placed on the catheter.
[0051] FIG. 13 shows the catheter after the 2 anterior stents 206a
and 2066 (not shown) have been deployed, and the anterior 710 and
separating 708a & 7086 rings are positioned on the free
guidewire 712 between the sphere 706 and the balloon 704. It may be
seen that the separating rings have annular protrusions 714
protruding from their outer surface. The purpose of these
protrusions is to protect the blood vessel inner wall from being
injured by the stents as the catheter travels through the vessel.
The posterior stent 206c is mounted on the distal half of the
balloon 704, while the anterior portion of the sliding ring 114
envelops the proximal end of the balloon. Thus, when the balloon is
inflated, only the distal half expands (since the sliding ring
resists the pressure of the balloon), expanding the stent 206c and
deploying it in the blood vessel.
* * * * *